Seriously, everyone attending is free to dress according to their own desire, style, and comfort level, within the bounds of what’s usual and customary to be worn, of course. You may participate in either boy or girl mode but please, not a mix of both.
Merida has a large gay community (and a few crossdressers) so it is very LGBT-friendly. The hotel and travel personnel are aware of the nature of the group. The Mayans are a happy, laid back people and welcome people of all persuasions. Still, remember, you are in a different culture so be sensitive to the ways in which they do things (no one is in a hurry). Always act politely, courteously and ladylike and you will accepted for the woman that you are
We ask that when you’re with the group, you dress appropriate to the occasion and activity, and act as a lady or gentleman, whichever you prefer at the time.